The subject of the present invention is the sealing of an end connection of a flat conductor made in particular in the form of a tubular flat braid.
Electrical conductors are frequently used which have a flat general shape and, in particular, are produced in the form of a wire braid made of an electrically conducting material, initially being in a tubular form and then being flattened, so as to assume a flat shape, and covered with an insulating protective sheath.
Flat braids of this type are used in particular for setting the screens of a high-voltage power-cable joint at the same potential, particularly for earthing them. Since such joints have to be perfectly insulated and sealed, it is also necessary to provide means for sealing the connection of the end of these flat-shaped conductors.
Thus, three flat braids are generally used, these having to be connected to an earth cable. In order to seal the connection, the ends of the three flat braids are placed one above another, the assembly is surrounded by an insulating material of the mastic type, which will fill the interstices of the ends of the three flat braids, and the entire assembly is gripped by means of a cold-recoverable sleeve or sheath which will also grip the earth cable made in the form of a round conductor.
Such a known construction has many drawbacks. This is because the sealing mastic carries the risk of creeping with variations in temperature, resulting in sealing defects. In addition, it is found in practice that, despite the use of the sealing mastic, the recoverable sleeve or sheath which grips the assembly cannot suitably come into contact with the mastic because of the flat shape of the braids, so that this may result in unprotected regions inside the sheath after recovery.
The object of the present invention is to eliminate these drawbacks and to considerably improve the sealing of an end connection of a flat conductor, particularly one made in the form of a tubular flat braid.
The sealing device for an end connection of a flat conductor, particularly one in the form of a tubular flat braid according to the invention, comprises a sleeve for sealing and protecting the connection, the sleeve being made of a cold-recoverable material which will grip the connection, and a rigid core, of convex outer surface, which is slipped into the end of the tubular flat braid. The assembly is gripped by the protective sealing sleeve.
The tubular flat braid or flat conductor is preferably covered with an insulating protective sheath which is capable of deforming during insertion of the rigid core.
The rigid core may advantageously have a cylindrical external shape. It may be made in the form of an at least partially hollow insert, for example in the form of a tube. The rigid core may also be a solid element such as a bar.
In order to make it easier to insert the rigid core, its end may be tapered or rounded.
The sealing device according to the present invention may be used to seal any end connection of a flat conductor.
One particularly advantageous application of the invention makes it possible to produce a sealing glove having one or more fingers, for the connection of several earth braids to an earth cable of a device for making the screens of a high-voltage power-cable joint an equipotential surface.